<template>
  <footer class="footer">
      <!-- This should be `0 items left` by default -->
      <span class="todo-count">剩余 <strong>{{shengyu}}</strong></span>
      <!-- Remove this if you don't implement routing -->
      <ul class="filters">
        <li>
          <a :class="{selected:flag===1}" @click="$emit('changeFlag',1)" href="#/">全部任务</a>
        </li>
        <li>
          <a :class="{selected:flag===2}" @click="$emit('changeFlag',2)" href="#/active">进行中</a>
        </li>
        <li>
          <a :class="{selected:flag===3}" @click="$emit('changeFlag',3)" href="#/completed">已完成</a>
        </li>
      </ul>
      <!-- Hidden if no completed items are left ↓ -->
      <button class="clear-completed" @click="$emit('clear')">清除已完成</button>
    </footer>
</template>

<script>
export default {
  props: {
    list:Array,
    flag:{
      required:true,
      type:Number
    }
  },
  //计算属性
  computed: {
    //计算未完成的数量
    shengyu() {
      return this.list.filter(item => item.isDone === false).length
    }
  }
}
</script>

<style>

</style>